


Do You Think They Heard Us?

by ShitL0rd



Category: Undertale (Video Game)
Genre: Alphyne, Ecto-Penis (Undertale), Ecto-Vagina (Undertale), Ectobiology, F/F, Fontcest, Ghost dicks, Jacking off, Lactation Kink, Light Somnophilia, M/M, Somnophilia, Unintentional Voyeurism, Vaginal Fingering, You get the idea, a big hotpot of filth, ecto boobs, sleep over fun times
Language: English
Status: Completed
Published: 2017-01-17
Updated: 2017-01-17
Packaged: 2018-09-18 02:33:59
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 1,308
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9362159
Author URL: https://archiveofourown.org/users/ShitL0rd/pseuds/ShitL0rd
Summary: Papyrus gets a little anxious when he wakes up from a wet dream. Sans is laying next to him in their sleeping bag. Papyrus would not have any problem asking his brother for assistance if it weren't for Undyne and Alphys sleeping in the same room a few yards away.





	

Papyrus squirmed as his pajama pants tightened uncomfortably. He peeked from underneath his cover and fought the urge to whine as his dick was fully erect.

Sleeping next to him was his older brother, and secret date. Sans always insisted on keeping their relationship lowkey, fearing the worst. Papyrus was always tempted to share with the world how happy and lucky he is to be with such a wonderful monster like Sans.

Papyrus leaned over and gently shook his sibling.

...

Nothing.

'Wonderful,' he thought. Well, maybe not so bad. Papyrus slowly lifted his hips and glided the head of his member against Sans' tailbone. A violent shudder ripped down his spine. If he had a botton lip, he'd be biting it right now.

Papyrus gave in to very restrained thrusts, trying his best not to disturb the other's slumber. Pre cum softened his pants and make this all the more enjoyable. Papyrus felt guilt well up in his soul. He was taking advantage of his resting brother for his own benefit. Sans wasn't even aware that this was happening! Just as Papyrus finished scolding himself, he pulled away and sighed.

Suddenly, a weak murmur came from the small lump beside him. Sans turned over, most likely half-asleep, and rubbed his eyes. 

"would ya quit wiggling around, bro? tryn'a sleep here," he stated in a soft, gentle whisper.

Papyrus slumped his shoulders and began to twiddle his fingers. A nervous habit he picked up when he was young. "Sorry, brother. I'm having difficulty staying alseep."

Sans groggily sat up. His voice was very hoarse. "wassa matter? need me to warm you up some milk?"

Papyrus gulped and blushed deeply. "W-well, I would like some milk." He hugged himself as lewd thoughts pushed into his skull. 

Sans released a heavy sigh and began to stand up. Then, the tugging on the hem of his loose t-shirt caught his attention. Turning around, he noticed Papyrus acting way out of character. "you okay, paps?"

Papyrus wearily chuckled. "Ah, y-yes... but..." He tightly shut his eyes and clenched his fists. "T-there is a certain kind of warm milk I want."

It took a while for Sans to process everything. He was a slow monster anyway. A blue blush dusted across his round cheeks. "o-oh. well, i dunno. undyne and alphys are like, a few feet away from us." He gingerly tilted his head to where the couple slept.

Papyrus solemnly looked up at Sans with large puppy eyes. "I'll be quiet. I promise!"

Sans sighed and blushed deeper. "a-alright." He sat himself up with the help of a few pillows, and conjured a small pair of breasts. They weren't the best, but still did the job. There was a soft blue glow emitting from the magic beneath his worn shirt. Wet spots already began to form from where the milk was coming out.

Papyrus bashfully lifted Sans' shirt and gently cupped his right breast. He was still fairly new with sex, and has only done something in that manner a few times. Sans didn't have much stamina in bed anyway. Not that Papyrus mined of course!

Papyrus dipped his head and flicked his tongue above the hardened nipple. Sweet, creamy liquid flowed with ease with a few squeezes to the boob. His eyes fluttered closed as he suckled. Papyrus lifted his other hand to give the left nipple similar treatment.

Sans hummed shyly and caressed his younger brother. He then shuddered as Papyrus gave a harsh squeeze, causing milk to spray lightly into his mouth. Sans quickly covered his mouth and moaned deeply. He began to spread his legs slighly, feeling a vagina forming.

Papyrus pulled back and kissed the left nipple and lighly bit down on it. He felt very confident now, noticing how Sans pushed back into him. Papyrus drank the warm milk in big gulps, taking in as much as he could. He massaged Sans' right upper-thigh and played with where his femur connected to his pelvis. 

Sans gasped sensually. He led Papyrus to his crotch and pressed their hands on the wet organ above his boxers. Papyrus groped and finally slipped his hand underneath the underwear. His long fingers played with the moist lips of the opening, enjoying the silk feel.

Papyrus pulled away, feeling proud that he had emptied Sans. Both of the breats' nipples were now very soft and cute. A few moments later, they dissipated. Papyrus changed positions with Sans, lifting his smaller body with ease. He then smirked and unbuttoned his pajama pants and pulled out his rather impressive length.

Sans' eye lights dialated in anticipation. "stars. bro, i-i don't think we can do this."

Papyrus chuckled and lifted the little monster and hovered his body above his throbbing erection. "I-It'll be okay, dear," he whispered. "We'll just have to be quiet." 

Before Sans could say more, he was slowly lowered onto the penis. He took in a large gasp of air and shuddered. He allowed himself to fully seat himself on his brother and wrapped his arms around their torso. "oh fuck!" he feebly wailed.

Papyrus kissed Sans and bucked his hips, beginning to find a comfortable rthym to follow. "H-hush, brother, and watch your language. Don't want to get caught, do we?"

Sans grinned and shook his head quickly.

***

Alphys stared back in shock in the dark. She could hear the faint, pleasured moans of her friends. She could hear the lewd squelch of their bodies meeting each other. She could hear Undyne breathing heavily into her ear.

"This shit turns you on, huh?" Undyne whispered huskily. She had slipped her scaly fingers beneath Alphy's panties and played with her clitorous.

Alphys whimpered and nodded her head. Her large glasses began to fog up. She would have never imagined her friends to screw themselves in her livingroom, let alone them being her ultra-secret-otp! 

She slowly pumped the tip of her tail into Undyne, blushing profusely. Maybe even enough for a nosebleed. Alphys could feel her lover's walls clench and suck her tail in deeper.

"Oh fuck, babe. Ngahh..." Undyne slid fingers into Alphys and began sizzoring her in time with the thrusts of her girlfriend's tail.

"I'm g-getting close!"

***

Sans lunged backward as Papyrus began to pound into him with vigor. He clenched his teeth together tightly, but failed at keeping the drool from escaping. 

"m-my pussy!!"

Papyrus groaned languidly and squeezed his brother tightly. Sweat beaded at his forehead and he took heavy breaths. His soul thumped frantically as his climax approached him at an increasing pace.

Sans couldn't help it. He couldn't. It was so good. He arched his back and wailed and he came hard onto his brother.

Papyrus had no time to scold Sans for nis outburst. He could feel the walls tighten and flutter around his cock, then sank him deep inside. "Goodness Sans! I'm-!!" Papyrus gasped and pumped his load into Sans, letting the pussy milk him thoroughly.

Sans blushed and sat still for a moment, staring at his brotherwith infatuation. He then lifted himself from Papyrus, and whimpered as creamy liquid flowed from his opening. "a-ah... oh stars." He threw himself onto the sleeping bag, thoroughly wrecked.

Papyrus followed suit, and embraced his brother in a warm hug. He sighed, allowing a goofy grin to make its way on his face. "You did wonderful, Sans. I'll let you sleep in tomorrow. You deserve some good rest."

Just as Sans was about to reply, they both heard a desperate squeal. Something that was very familiar. A squeal that only one monster in this room makes...

Alphys.

Sans' skull turned a raging dark blue and he quickly faced Papyrus and shoved his face into his chest. 

"Nyeh! What was that?" he whispered.

"probably a mouse."

"Oh..." Papyrus returned the cuddle and blushed. "Do you think they heard us?"

**Author's Note:**

> Kudos and Comments are greatly appreciated! ^▼^


End file.
